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BUG: KASAN: use-after-free in rose_get_neigh+0x17e/0x550 net/rose/rose_route.c:692
Read of size 1 at addr ffff888057a1c030 by task syz.7.595/7454

CPU: 0 PID: 7454 Comm: syz.7.595 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x220 mm/kasan/report.c:427
 kasan_report+0x10b/0x140 mm/kasan/report.c:531
 rose_get_neigh+0x17e/0x550 net/rose/rose_route.c:692
 rose_connect+0x412/0x1380 net/rose/af_rose.c:816
 __sys_connect_file net/socket.c:2011 [inline]
 __sys_connect+0x389/0x410 net/socket.c:2028
 __do_sys_connect net/socket.c:2038 [inline]
 __se_sys_connect net/socket.c:2035 [inline]
 __x64_sys_connect+0x76/0x80 net/socket.c:2035
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1de878e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1de95a4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f1de89b6080 RCX: 00007f1de878e969
RDX: 0000000000000040 RSI: 00002000000001c0 RDI: 0000000000000007
RBP: 00007f1de8810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1de89b6080 R15: 00007ffd7cda8a58
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00015e8700 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57a1c
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00017c5208 ffffea0001cbb588 0000000000000000
raw: 0000000000000000 0000000000100000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6724, tgid 6724 (modprobe), ts 320585367445, free_ts 366619511545
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5606
 alloc_slab_page+0x5d/0x160 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x87/0x2c0 mm/slub.c:1992
 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180
 kmem_cache_alloc_bulk+0x1a3/0x4e0 mm/slub.c:3830
 mt_alloc_bulk lib/maple_tree.c:157 [inline]
 mas_alloc_nodes+0x449/0x890 lib/maple_tree.c:1299
 mas_node_count_gfp lib/maple_tree.c:1359 [inline]
 mas_preallocate+0x11e/0x340 lib/maple_tree.c:5805
 do_mas_align_munmap+0x1f3/0x1220 mm/mmap.c:2441
 do_mas_munmap+0x240/0x2b0 mm/mmap.c:2638
 __mmap_region mm/mmap.c:2686 [inline]
 mmap_region+0x713/0x1d30 mm/mmap.c:2904
 do_mmap+0x894/0xf30 mm/mmap.c:1424
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1470
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3422
 getname_flags+0xb7/0x500 fs/namei.c:139
 vfs_fstatat fs/stat.c:266 [inline]
 __do_sys_newfstatat fs/stat.c:437 [inline]
 __se_sys_newfstatat fs/stat.c:431 [inline]
 __x64_sys_newfstatat+0x134/0x1e0 fs/stat.c:431
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff888057a1bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888057a1bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888057a1c000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff888057a1c080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888057a1c100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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